Reducing and separating machine



No. 752,044. PATENTED FEB. 16, 1904.

E. B. CRAVEN.

REDUCING AND SEPARATING MACHINE.

APPLIGATION FILED N016. 1903.

N0 MODEL. I I 2 SHEETS-SHEET 1.

No. 752,044. PATENTED FEB. 16, 1904. E. B. CRAVEN. I REDUCING AND SEPARATING MACHINE.

APPLICATION FILED NOV. 6.1903.

N0 MODEL.

9 a L l I UNITED STATES Patented February 1c, 1904.

ATENT OFFICE.

ENOCH BASCOMB CRAVEN, OF ASBESTOS, GEORGIA. I

FI EDUCING AND SEPARATING MACHINE.

SPECIFICATION forming part of Letters Patent No. 752,044, dated February 16, 1904.

Application filed November 6, 1903. Serial No. 180,079- (No model.)

fans which discharge the product into dust collectors, the imperfectly-reduced material being returned to the reduction-chamber,

while the properly-reduced and purified material is discharged at proper places.

My invention has special reference to that class of devices in which the same air-currents operate continually with but little accession or fresh supply of air from the'ontside.

My invention has for its object to provide a machine of this class specially adapted to operate upon low-grade asbestos for the purpose of reducing and fiberizing the same and also for the purpose of separating the same from foreign substances; and with these and other ends in view it consists in the improved construction, arrangement; and combination of "parts, which will be hereinafter fully described, and particularly pointed out in the claims.

In the accompanying drawings, Figure l is a side elevation, partly broken, of the main separator of my improved system. Fig. 2 is a horizontal sectional view taken on the line 2 2 in Fig. 1. Fig. 3 is a detail elevation of the separator, taken at right angles to Fig.1 and with the outer casing largely removed. Fig. 4 is a perspective detail view of one of the collapsible deflectors. 5 is a diagrammatic view showing the various parts comprising my improved device in approximate relation to each other. Fig. 6 is a sectional detail view taken on the line 6 6 in Fig. 5. 5

Corresponding parts in the several figures are indicated by similar numerals of reference. In carrying out my invention I avail mysel} of two separate reduction devices characterized, respectively, as the large mill 1 and the small mill 2; These mills or reduction devices have been indicated conventionally only, and no improvement is at present claimed in the construction of these devices. In practice they are located adjacent to each other, as clearly shown in Fig. 1, and are provided with power-shafts 3, having belt-pulleys 4.

5 is a large separating-chamber, indicated in the drawings as being octagonal; in crosssection and tapering toward its upper and lower ends. This large separator has a central partition 6 extending through its entire length and dividing the same into two chambers or compartments which are distinctly separated from each other, said compartments being designated, respectively, 7 and 8. It is obvious that two entire separate compartments might be used; but the construction herein shown has been chosen on account of its general convenience, saving in space, and other advantages.

Each of the compartments 7 and 8 of the separator is provided with partitions 9 and 10, said partitions combining to form an octagon chamber, the Walls of which are parallel to those of the outer octagon but be ing divided by the central partition 6 each of the partitionsi) and 10 has five sides provided at their upper ends with shafts catryingdeflectors 11, having operating-rods 8 extending through nipples 9 in the walls of the outer octagon and which by manipulating said operating-rods may be adjusted in various positions, as will be seen indicated by dotted lines in Fig. 1, and secured in adjusted position by means of set-screws 10 in the nipples 9. Each of the chambers 7 and 8 is thus divided into subcompartments, designated, re-' spectively, 7 7 and 8 8 the compartments 7 a and 8" being connected by means of pipes '12 and 13, respectively, with the large mill and the small mill. Thelower ends of the subcompartments 7 and 8 communicate with automatic valves 14: and 14 for the escape of the material accumulating in said compartments. The pairs of valves 14 and 14: disposed in the discharge-tubes are designated asthe upperand lower valves, respectively. The upper valves 1d are counterbalanced byweights 14 in such a manner as to remain closed against a certain weight of material deposited upon said valves. The valves 14 are likewise counterbalanced by weights 14?. WVhen material is shed from the upper valve 14, the inrush of air caused by suction created in the upper part of the separator by means to be hereinafter described will close the lower valve 14, upon which the material shed from the valve 14 will thus be deposited. As soon as the lower valve receives a suflicient weight of material it opens, and the inrushing air will close and retain in a closed position the upper valve, thus cutting off the air-current and permitting the lower'valve to remain open until the upper valve again accumulates a suflicient load to partly open and admit of the passage of suflicient air to cause a pressure, whereby the lower valve is closed. The operation is then repeated, as before.

The upper ends of the compartments 7 and 8 are connected by means of pipes 15 and 16 with the eyes of fan-casings 17 and 18, containing ordinary suction-fans which discharge into thedust-collectors 19 and 20. The latter, the construction of which will be presently more fully described, are provided with air-exit pipes 21 and 22, leading to the pipes 12 and 13, through which an upward current is induced from the reduction-chambers, as has been already described.

The upper parts of the chambers 7 and 8 of the separator are provided with downwardlyextending deflectors 23 and 24. Thus when the reduced material rises from the mills suspended in the circulating air currents the greater portion of the finished product is carried through the pipes 15 and 16 through the fans to the dust-collectors. A portion of the unfinished product returns by gravity to the mill, and a portion of the unfinished as well as the finished product falls back over the neath the rotary screen.

movable deflectors into the subcompartments 7" and 8, being discharged from the valves 14 into a rotary screen or reel 25, which takes these products, being rotated by means of properly-applied power, and being further disposed in an inclined position, as shown clearly in Fig. 5, will discharge through its meshes the fine hard products which are conveyed to the small mill by means of a spiral conveyer 26, disposed in a trough 27, arranged under- The long fibrous product which is discharged at the tail end of the screen 25 is dumped into a hopper 28, which is connected, by means of a pipe 29,with a gravity-separator 30, which is connected by a suction-pipe 31 with a fan-casing 32, which discharges into the dust-collector 33, the exhaust-pipe of which 34 connects with the lower end of the gravity-separator 30, which latter is provided with suitably-disposed deflectors 35. Beneath said deflectors the gravity-separator discharges into a hopper 36, connected with a trough 37 containing a spiral conveyer 38, the latter discharging into the casing of the large mill.

It will be seen from the foregoing that the material discharged from the subchambers 7 8 through the valves 14 passes through the rotary screen, the screenings being immedidiately reconveyed to the small mill for further reduction. The long fibrous product being discharged into the hopper 28 rises from the latter suspended in the air-current induced by the fan within the casing 32 into the gravity-separator 30. The heavy and com paratively unclean product will drop from said separator into the hopper 36, from whence it is reconveyed to the large mill to be further reduced and separated. The long clean fibrous product is carried suspended in the air-current through the fan-casing 32 to the dustcollector 33, where its final cleansing is accomplished and at the bottom of which it is discharged. Be it understood that the product discharged at this point is the superior or firstgrade material.

It has been already set forth how part of the material rising from the two mills in a re duced state is carried through the pipes '15 and 16 and the fan-casings 17 and 18 into the dust-collectors 19 and 20. These collectors are larger than the dust-collectors 33, for the reason that the major part of the finished productis discharged through these devices. It is important that the pressure of the air-current entering these dust-collectors should be carefully regulated, and for the purpose of automatically accomplishing this I provide each of the pipes 15 and 16 prior to the point at which it enters its respective fan-casing with an automatic air-governor comprising an air-motor 40, disposed in an enlarged portion of said air-pipe and mounted upon a shaft 41, carrying a pulley 42, connected by means of a belt 43 with a pulley 44,-mounted upon a shaft 45, which is journaled in a bracket 46, suitably connected with the airpipe. The pipe 45 also carries a bevel-pinion 47 connected with a bevel-gear 48, which is journaled upon a tubular shaft 49, mounted securely in the bracket 46.

50 is aperforated plate. 51 and 52 are links connecting said perforated plate and the pinloo its

ion '48 with the governor-weights 53, which ernor will operate to limit the amount of air permitted to enter the fan-casing connected with either of the mills through the compartments of the large sepa'rator.

The dust-collectors used in connection with my invention are of the ordinaryfrusto-conical shape, having cylindrical upper ends which are provided at the sides thereof with inlets '56" for the air-currents from the fancasings. These air-currents are guided by interiorly-disposed partitions in a spiral direction, thence upwardly into chambers 57, located on top of the respective casings and provided at the sides thereof with outlets for the air-currents, which are disposed all in the manner previously described. Thefinished product is discharged at the bottom of the dust-collectors, the second-grade product being discharged from the collector 19, connected with the large mill, and the third-grade product from the collector 20, connected with the small mill. Each of'the dust-collectors also has a discharge pipe 60, carrying the surplus dust-laden air to a closed bin. (Not I shown.)

In operation the asbestos ore or low-grade asbestos is fed principally tothe large mill 1 through a hopper provided upon the casing of said mill or upon the pipe rising from said casing. Screenings or inferior grades may be fed to the small mill. The reduced material from both mills will rise through the pipes 15 and 16 and be treated anddisposed of as already described, the screenings and inferior material only being returned to the small mill, while the large mill receives the superior grade of screenings. By this device a very low grade of asbestos may be made to yield very useful products which are auto- 'matically graded,-and no portion of any utility whatever is permitted to go to-waste.

It may be found desirable to divide the-aircurrent ascending the compartments 7 and 8 of the separator, and I therefore arrange in said chambers or compartments deflectors 61, each composed of a frame, the sides of which 62 are hingedly jointed together, one of said sides being attached to the wall of the partition 9 or 10. The upper corner of each frame is connected with-the lower end of an operatingrod 63, which extends upwardly through a 4 nipple 64-. in'the casing, so that it may be readilymanipulated to fold or to. expand the deflector, as may be desired, said deflector being mounted pivotally upon the hinge-pin 66 atits lower corner. A set-screw in the nipple serves to hold the'operating-rod in'its 6o 4 i a ir of reduction mills, aseparatorhavmg compartments connected withthe said,

adjusted position. v a a Having thus described my invention, I

1. Adevice oftheclass described, compris mills and subcompartmentsprovided with discharge-valves, partitions within the compartments, movable deflectors at the upper ends of said partitions, stationary deflectors in the npperpart of the separator-chambers, means for inducing air-currents through theseparator-cliambers and through fan-casings, dustcollectors receiving the air-currents and the particles suspended therein from the fan-cas ings', and means for returning the air-cur: rents from the upper ends of the dust-collectors tothe-reduction-mills 2. In a device of the class described, a large and a small reduction-mill, a separator having two compartments, partitions in said compartments dividing the same into subcompartments, pipes connecting the lower ends of the outer subcompartments with the large and small mills respectively, discharge-valves at the lower ends of the inner subcompartments, movable deflectors at the upper ends of the partitions, stationary deflectors in the upper ends of the compartments of the casing, a pair of fan-casings and a pair of dust-collectors, means for setting up air-currents in said fan-casings, suction-pipes connecting the latter with the respective compartments of the separator, discharge-pipes connecting said fan-casings with the dust-collectors, pipes for returning the air from the latter to the reduction mills, and automatically operated means for regulating the speed and intensity of the air-currents.

3. In a device of the class described, a large and a small reduction-mill, a separator having compartments communicating with said mills and other compartments having dischargevalves at their lower ends,means for setting up currents of air upwardly in'the compartments connected with the mills, deflectors disposed. to convey portions of the material suspended in said air-currents into the compartments having the discharge-valves, a rotary screen disposed to receive the discharge from said valves, a conveyor disposed below said I screen to convey the screenings to the small mill, a hopper disposed to receive the dis charge from the screen, a gravity-separator,

means for setting up an air-current throughsaid gravity-separator from the hopper receiving the discharge from the screen, a dustcollector receiving the said air-current and the particles suspended therein, a return-pipe leading from the upper part of said dust-collector to the lower end of the gravity-separator, a' hopper disposed beneath the latter to receive the products separated by gravitatiOH,

and means for conveying said products from said hopper to the casing of thelarge mill. v

4. In adevice of the class described, a sepa;

rater, octagonal in cross-section, a central par tition within said separator, partition-walls within each of the compartments thus formed, the sides of said partition walls be ng parallel with the walls of the outer octagon, deflectors hingedly connected with the upper ends of each &

of the sides of the inner octagon, operatingrods connected with said deflectors, nipples in the outer casing for the passage of said operating-rods, and means for securing the latter in adjusted position.

5. In a device of the class described, a separator-casing, a central vertical partition within the same, a concentric partition-wall bisecting each of the compartments formed by the cen- I tral partition, and collapsible deflectors mountmy own I have hereto aflixed my signature in the presence of two witnesses.

ENOCH BASCOMB CRAVEN.

Witnesses:

ALEX DAVIDSON, J. H. BRACKETT. 

